Fix Slow Page Loading Issue in Mozilla Firefox

Mozilla Firefox is one of the most popular browsers out there. It still maintains a sizable market share and user base. Developers from Mozilla constantly release updates to make Firefox faster and better. People love Firefox because it has relatively low memory consumption, better privacy and supports a good selection of add-ons.

But you may feel that Firefox started loading pages slowly over the period of time, especially after updating to new version. We have previously explained how to fix slow page loading issue in Google Chrome and Mac Safari. In this article let us discuss how to fixe slow page loading issue in Mozilla Firefox.

Fix Slow Page Loading Issue in Mozilla Firefox

Try below tips to improve the page loading and speedup Firefox.

Minimize memory usage

Use safe mode or disable add-ons (Restart with add-ons disabled)

Refresh Firefox

Disable antivirus and firewall applications

Change startup preferences

Disable auto update

Increase content process limit

Disable network proxy

Uncheck autoscrolling and smooth scrolling options

Clear browsing history and remember history

Increase cached web content size

Prevent accessibility services

Enable browser cache

Enable pipelining [before release 54]

Disable animation

Disable DNS prefetching

Adjust connections per server

Increase content notify interval

Reduce content switch threshold

Use performance-enhancing add-ons

Manage Flash

Use lighter adblocking tool

Use Latest Firefox Quantum

Delete and reinstall Firefox

1. Minimize Memory Usage

Firefox doesn’t regularly release RAM that it already uses. As Firefox consumes more and more RAM, your computer will lose its performance. Follow these steps to tell Firefox to reduce RAM usage:

Type “about:memory” in the address bar and hit Enter.

Go to “Free memory” heading and choose Minimize memory usage.

Minimize Firefox Memory Usage

2. Start with Safe Mode

Extensions and add-ons take resources and make your Firefox runs slower. It can be quite tempting to install more than a few add-ons, because you may get new useful features that make your browsing experience fun and more productive. Remove add-ons that you no longer need, you can always re-install them later. Go to the menu option “Help > Restart with Add-ons Disabled…” and you will be prompted to restart the browser. On the next dialog box click on the “Start in Safe Mode” button to restart Firefox.

Open Firefox in Safe Mode

Safe mode allows Firefox to disable all installed add-ons and custom settings. So this is very useful if the add-ons are causing slow page loading. You can disable the safe mode by going to “Help > Restart with Add-ons Enabled…” option.

If the browser works fast in safe mode then one of the installed add-ons might be causing the issue. After enabling all add-ons, go to “about:addons” and disable the add-ons one by one to find which one is causing the slowness.

3. Refresh Firefox

When starting Firefox in safe mode, you can see an additional option called “Refresh Firefox”. Clicking on this option will help you to reset Firefox to initial factory settings. Check whether this helps to push slow loading pages.

Refresh Firefox

4. Disable Antivirus And Firewall Applications

Firefox is built for security and privacy. This may conflict with your antivirus or firewall settings on your computer. So it’s a good idea to disable the additional protection settings on your computer and check it helps to improve the page loading speed in Firefox. If not, you can enable them back.

5. Change Startup Preferences

Firefox will load the default startup page with top sites and highlights. This may slow down the browser whenever you open new tab page. You can change it under “General” section by going to “about:preferences”.

Change Startup and Home Page in Firefox

Select “Show a blank page” option to speed up opening new tab page.

6. Disable Auto Update

By default Firefox automatically updates to the newest version. This may cause trouble as it can affect the speed as well as the functionalities. So, disable the auto update feature and enable “Check for updates but let you choose to install them” option. This option is available in “General > Firefox Updates” section under “about:preferences”.

Disable Auto Update in Firefox

7. Increase Content Process Limit

Firefox automatically determines the performance settings based on your computer’s hardware and operating system. This may not be ideal in all cases and affect the browsing experience inadvertently. Go to “about:preferences#general” and navigate to “Performance” section.

Disable the option “Use recommended performance settings” and you can see the default value of Firefox multiprocess feature is 4. Increase the content process limit to 7 using the dropdown menu.

Change Recommended Performance Settings

If Firefox starts to crash when you are browsing, reduce the value to 6 or 5 to achieve a good balance between stability and performance.

8. Disable Network Proxy

Go to “about:preferences”, navigate to bottom of the page under “General” section and click on the “Settings” button for “Network Proxy” option. Choose “No proxy” option and click “OK”.

10. Clear Browsing History And Remember History

During normal browsing sessions, Firefox stores scripts and images in a local cache. When you revisit the same page, these files can be retrieved locally from your computer, resulting in faster loading of the webpage. Sometimes the corrupted cache and cookies may cause slow loading of web pages.

11. Increase Cached Web Content Size

If you have enough RAM (4GB or more); you may increase Firefox’s local browser cache size to improve its performance. Follow these steps:

Type “about:config” in the address bar and hit Enter.

Right click anywhere on the tab window and choose “New > Integer” in the context menu.

Type “browser.cache.memory.capacity” and click OK.

Set 65536 as its value and click OK.

Restart Firefox.

Remember when you open the configuration page, Firefox will warn you about the risk. You should accept the risk in order to do configuration changes.

You can also change the cache size by going to “about:preferences#privacy” under “Cached Web Content” section. Enable the checkbox “Override automatic cache management” and enter the size of the cache.

Change Cached Web Content Size

12. Prevent Accessibility Services

Accessibility services allow Firefox to interact with the third party services for helping disabled people. This may make Firefox unstable and affect the performance. Go to “about:preferences#privacy” and navigate to “Permissions” section.

13. Enable Browser Cache

Firefox by default should have the browser cache enabled. Browser cache is a feature that’s aimed to improve the page loading speed performance. Follow these steps to check if browser cache is enabled on your Firefox browser and enable it if not:

Type “about:config” in the Firefox address bar and hit Enter.

You will see a list of all advanced browser settings. Paste “browser.cache.disk.enable” in the search box to filter the entries.

The default value should be “true”. If it is set as “false”, right click and click “Toggle” to change the value to “true”.

Close the “about:config” tab and restart Firefox.

Toggle Browser Cache Preference Value in Firefox

Enabling cache will definitely help to store the content of the visited pages and improve the loading speed when the same page is loaded again.

14. Enable Pipelining [Before Release 54]

Mozilla Firefox can be very polite. After it sends a request, it will wait for a response from the server before continuing. By enabling pipelining, you can make Firefox more aggressive. It will send multiple requests without waiting for responses. After enabling pipelining, you may often notice significantly reduced webpage loading time.

Follow these steps

Type about:config in the address bar and hit Enter.

Locate and double click on ‘network.http.pipelining’. Change its value to True.

Locate and double click on ‘network.http.proxy.pipelining’. Change its value to True.

Locate and double click on ‘network.http.pipelining.maxrequests’. Change its value to 8.

Restart Firefox.

Pipelining was removed from version 54 as Firefox moves to HTTP/2.

15. Disable Animation

Firefox should perform better if you disable animation. Follow these steps:

Type “about:config” in the address bar and hit Enter.

Type ‘animate’ in the search bar. After you find the appropriate entry, set it to False.

Restart Firefox.

Remember the animation preference entries may differ based on the version of Firefox you are using.

16. Disable DNS Prefetching

DNS prefetching helps to fetch the content of the linked pages before you actually click and visit them. Generally this option is set as false as it will affect the performance of the currently viewed pages. In certain cases, enabling this can help to improve the speed especially the linked pages.

Go to “about”config” and search for “network.dns.disablePrefetch” preference option. Right click and click on the “Toggle” to change the value to “true”.

17. Adjust Connections Per Server

Firefox limits the simultaneous number of connection to a web server to 6 by using HTTP keep-alive connections. You can increase the value of the preference “network.http.max-persistent-connections-per-server” in configuration to 10.

Remember this will increase the number of connections to the server. Though the number can be 1 to 255, never use more than 10. Otherwise the site owner may block your IP address due to large number of simultaneous requests.

18. Increase Content Notify Interval

Even with a powerful computer and fast Internet connection, it may take awhile to open complex, large webpages. By default, Firefox displays everything that it receives from the web every 0.12 seconds. However, you can get longer total page load time with frequent redraws, so it is better to increase the value of content notify interval. Follow these steps

Type “about:config” in the address bar and hit Enter.

Right click anywhere on the tab window and choose “New > Integer” in the context menu.

Type “content.notify.interval” and click OK.

Set 500000 (with five zeroes) as its value and click OK.

Add Integer Preference Value in Firefox

Right click anywhere on the tab window again and choose “New> Boolean” in the context menu.

Type “content.notify.ontimer” and set its value to True. Click OK.

Add Boolean Value in Firefox Preference

Restart Firefox and check the pages are loading faster.

19. Reduce Content Switch Threshold

Firefox goes into the low frequency interrupt mode, if you haven’t touched the keyboard or moved the mouse for 0.75 seconds. This allows webpages to load quicker, but the interface is slightly less responsive. You can improve performance by reducing the content switch threshold. Follow these steps:

Type “about:config” in the address bar and hit Enter.

Right click anywhere on the tab window and choose “New > Integer” in the context menu.

Type “content.switch.threshold” and click OK.

Set 250000 (with four zeroes) as its value and click OK.

Restart Firefox.

Firefox will enter the low frequency interrupt mode in just 0.25 seconds. It will be faster for webpages to load.

Ensure you have set true value for content.notify.ontimer and content.interrupt.parsing for this preference to take effect.

20. Use Performance-Enhancing Add-Ons

Although add-ons are often said to cause performance degradation, some may speed-up Firefox. Here are a few add-ons that you may consider:

OneTab: converts all open tabs into a list and you can retrieve individual page or all tabs. This will help to save lot of memory occupied by the Firefox.

Image Block X: It blocks images on websites, resulting in faster browsing experience. Even if you have fast Internet access, it will require less memory to load pages without images, ensuring smoother performance.

Speed Tweaks: It automatically performs tweaks in about:config to increase performance, so you don’t need to do them manually.

21. Manage Flash

Flash animations on web browsers can be very intrusive. They pop up everywhere and slow down your browsing experience. It’s easy to remove them completely, by installing any of the Flash blocking extensions. After all Flash applets are blocked, web pages should load much faster. However, in some cases, you may still want to view Flash content to get information or play games. In this case, Flash content won’t be loaded, but you can still play by installing Adobe Flash plugin and set the option as “Ask to Activate”. This will prevent Firefox from automatically running Flash content.

22. Use Lighter Adblocking Tool

Adblock is a popular adblocking tool, but it may reduce Firefox performance, if you have a slow computer. The add-on “uBlock Origin” is a lightweight alternative you can use to replace Adblock, because it manages CPU and RAM better, resulting in better performance. In case, there’s a doubt, uBlock removes ads effectively as well.

23. Use Latest Firefox Quantum

The latest Firefox Quantum has lot of performance improvements. So update to the latest version and check whether it resolves your problems.

Install Latest Firefox

24. Delete And Reinstall Firefox

If none of the above solutions work for you then the last option is delete Firefox completely and do a clean install again.

Conclusion

By implementing all of these performance enhancing solutions, you should get noticeable improvement in browsing experience. When messing with “about:config” entries, you should be careful and follow the instruction. Any improper change could affect Firefox performance in a negative way.

About Editorial Staff

1 Comment

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Nice article. But in my case what delayed the page load was the built-in Content Blocking feature. It was taking 5 secs to load the page that Chrome was loading almost instantly, I checked it out in the console and noticed Content Blocking warnings of Firefox. After disabling Content Blocking, Firefox loaded the page even faster than Chrome. I guess it analyses the page to deduce the content it’s going to block before loading, because you can see that page actually loads (loading indicator disappears on the tab bar) but it takes a bit to block the content, hence the delay.

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